core, eth, les, rpc: polish catalyst errors, add context

Author: karalabe

core/beacon/errors.go

@@ -21,6 +21,39 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
+// EngineAPIError is a standardized error message between consensus and execution
+// clients, also containing any custom error message Geth might include.
+type EngineAPIError struct {
+	code int
+	msg  string
+	err  error
+}
+
+func (e *EngineAPIError) ErrorCode() int { return e.code }
+func (e *EngineAPIError) Error() string  { return e.msg }
+func (e *EngineAPIError) ErrorData() interface{} {
+	if e.err == nil {
+		return nil
+	}
+	return struct {
+		Error string `json:"err"`
+	}{e.err.Error()}
+}
+
+// With returns a copy of the error with a new embedded custom data field.
+func (e *EngineAPIError) With(err error) *EngineAPIError {
+	return &EngineAPIError{
+		code: e.code,
+		msg:  e.msg,
+		err:  err,
+	}
+}
+
+var (
+	_ rpc.Error     = new(EngineAPIError)
+	_ rpc.DataError = new(EngineAPIError)
+)
+
 var (
 	// VALID is returned by the engine API in the following calls:
 	//   - newPayloadV1:       if the payload was already known or was just validated and executed
@@ -43,10 +76,10 @@ var (
 
 	INVALIDBLOCKHASH = "INVALID_BLOCK_HASH"
 
-	GenericServerError       = rpc.CustomError{Code: -32000, ValidationError: "Server error"}
-	UnknownPayload           = rpc.CustomError{Code: -38001, ValidationError: "Unknown payload"}
-	InvalidForkChoiceState   = rpc.CustomError{Code: -38002, ValidationError: "Invalid forkchoice state"}
-	InvalidPayloadAttributes = rpc.CustomError{Code: -38003, ValidationError: "Invalid payload attributes"}
+	GenericServerError       = &EngineAPIError{code: -32000, msg: "Server error"}
+	UnknownPayload           = &EngineAPIError{code: -38001, msg: "Unknown payload"}
+	InvalidForkChoiceState   = &EngineAPIError{code: -38002, msg: "Invalid forkchoice state"}
+	InvalidPayloadAttributes = &EngineAPIError{code: -38003, msg: "Invalid payload attributes"}
 
 	STATUS_INVALID         = ForkChoiceResponse{PayloadStatus: PayloadStatusV1{Status: INVALID}, PayloadID: nil}
 	STATUS_SYNCING         = ForkChoiceResponse{PayloadStatus: PayloadStatusV1{Status: SYNCING}, PayloadID: nil}

eth/catalyst/api.go

@@ -166,10 +166,10 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update beacon.ForkchoiceStateV1, pa
 		finalBlock := api.eth.BlockChain().GetBlockByHash(update.FinalizedBlockHash)
 		if finalBlock == nil {
 			log.Warn("Final block not available in database", "hash", update.FinalizedBlockHash)
-			return beacon.STATUS_INVALID, &beacon.InvalidForkChoiceState
+			return beacon.STATUS_INVALID, beacon.InvalidForkChoiceState.With(errors.New("final block not available in database"))
 		} else if rawdb.ReadCanonicalHash(api.eth.ChainDb(), finalBlock.NumberU64()) != update.FinalizedBlockHash {
 			log.Warn("Final block not in canonical chain", "number", block.NumberU64(), "hash", update.HeadBlockHash)
-			return beacon.STATUS_INVALID, &beacon.InvalidForkChoiceState
+			return beacon.STATUS_INVALID, beacon.InvalidForkChoiceState.With(errors.New("final block not in canonical chain"))
 		}
 		// Set the finalized block
 		api.eth.BlockChain().SetFinalized(finalBlock)
@@ -179,21 +179,19 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update beacon.ForkchoiceStateV1, pa
 		safeBlock := api.eth.BlockChain().GetBlockByHash(update.SafeBlockHash)
 		if safeBlock == nil {
 			log.Warn("Safe block not available in database")
-			return beacon.STATUS_INVALID, &beacon.InvalidForkChoiceState
+			return beacon.STATUS_INVALID, beacon.InvalidForkChoiceState.With(errors.New("safe block not available in database"))
 		}
 		if rawdb.ReadCanonicalHash(api.eth.ChainDb(), safeBlock.NumberU64()) != update.SafeBlockHash {
 			log.Warn("Safe block not in canonical chain")
-			return beacon.STATUS_INVALID, &beacon.InvalidForkChoiceState
+			return beacon.STATUS_INVALID, beacon.InvalidForkChoiceState.With(errors.New("safe block not in canonical chain"))
 		}
 	}
-
 	valid := func(id *beacon.PayloadID) beacon.ForkChoiceResponse {
 		return beacon.ForkChoiceResponse{
 			PayloadStatus: beacon.PayloadStatusV1{Status: beacon.VALID, LatestValidHash: &update.HeadBlockHash},
 			PayloadID:     id,
 		}
 	}
-
 	// If payload generation was requested, create a new block to be potentially
 	// sealed by the beacon client. The payload will be requested later, and we
 	// might replace it arbitrarily many times in between.
@@ -202,14 +200,14 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update beacon.ForkchoiceStateV1, pa
 		empty, err := api.eth.Miner().GetSealingBlockSync(update.HeadBlockHash, payloadAttributes.Timestamp, payloadAttributes.SuggestedFeeRecipient, payloadAttributes.Random, true)
 		if err != nil {
 			log.Error("Failed to create empty sealing payload", "err", err)
-			return valid(nil), &beacon.InvalidPayloadAttributes
+			return valid(nil), beacon.InvalidPayloadAttributes.With(err)
 		}
 		// Send a request to generate a full block in the background.
 		// The result can be obtained via the returned channel.
 		resCh, err := api.eth.Miner().GetSealingBlockAsync(update.HeadBlockHash, payloadAttributes.Timestamp, payloadAttributes.SuggestedFeeRecipient, payloadAttributes.Random, false)
 		if err != nil {
 			log.Error("Failed to create async sealing payload", "err", err)
-			return valid(nil), &beacon.InvalidPayloadAttributes
+			return valid(nil), beacon.InvalidPayloadAttributes.With(err)
 		}
 		id := computePayloadId(update.HeadBlockHash, payloadAttributes)
 		api.localBlocks.put(id, &payload{empty: empty, result: resCh})
@@ -248,7 +246,7 @@ func (api *ConsensusAPI) GetPayloadV1(payloadID beacon.PayloadID) (*beacon.Execu
 	log.Trace("Engine API request received", "method", "GetPayload", "id", payloadID)
 	data := api.localBlocks.get(payloadID)
 	if data == nil {
-		return nil, &beacon.UnknownPayload
+		return nil, beacon.UnknownPayload
 	}
 	return data, nil
 }

les/catalyst/api.go

@@ -98,7 +98,7 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(heads beacon.ForkchoiceStateV1, pay
 
 // GetPayloadV1 returns a cached payload by id. It's not supported in les mode.
 func (api *ConsensusAPI) GetPayloadV1(payloadID beacon.PayloadID) (*beacon.ExecutableDataV1, error) {
-	return nil, &beacon.GenericServerError
+	return nil, beacon.GenericServerError.With(errors.New("not supported in light client mode"))
 }
 
 // ExecutePayloadV1 creates an Eth1 block, inserts it in the chain, and returns the status of the chain.
@@ -157,7 +157,7 @@ func (api *ConsensusAPI) checkTerminalTotalDifficulty(head common.Hash) error {
 	// make sure the parent has enough terminal total difficulty
 	header := api.les.BlockChain().GetHeaderByHash(head)
 	if header == nil {
-		return &beacon.GenericServerError
+		return errors.New("unknown header")
 	}
 	td := api.les.BlockChain().GetTd(header.Hash(), header.Number.Uint64())
 	if td != nil && td.Cmp(api.les.BlockChain().Config().TerminalTotalDifficulty) < 0 {
@@ -176,7 +176,7 @@ func (api *ConsensusAPI) setCanonical(newHead common.Hash) error {
 	}
 	newHeadHeader := api.les.BlockChain().GetHeaderByHash(newHead)
 	if newHeadHeader == nil {
-		return &beacon.GenericServerError
+		return errors.New("unknown header")
 	}
 	if err := api.les.BlockChain().SetCanonical(newHeadHeader); err != nil {
 		return err

rpc/errors.go

@@ -54,7 +54,6 @@ var (
 	_ Error = new(invalidRequestError)
 	_ Error = new(invalidMessageError)
 	_ Error = new(invalidParamsError)
-	_ Error = new(CustomError)
 )
 
 const defaultErrorCode = -32000
@@ -102,12 +101,3 @@ type invalidParamsError struct{ message string }
 func (e *invalidParamsError) ErrorCode() int { return -32602 }
 
 func (e *invalidParamsError) Error() string { return e.message }
-
-type CustomError struct {
-	Code            int
-	ValidationError string
-}
-
-func (e *CustomError) ErrorCode() int { return e.Code }
-
-func (e *CustomError) Error() string { return e.ValidationError }